Mechanical time-fuse



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' Jfawamzmz Gnyf, y k M Patented Aug. 5, 1919.

ULY 6. |918 MECHANICAL TIME FUSE.

H. M. GROFF.

MECHANICAL TIME FUSE.

APPLICATION FILED JULY 6.19m.

1 ,3 1 2, 1 1 2. Pmemed Aug. 5, 1919.

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Howard JZ. Gfqff; .ley wl @am Atty?.

H. VI. GROFF.

MECHANICAL TIME FUSE. APPLICATION man JULY 6. |919.

Patented Aug. 5, 1919.

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HOWARD ivi. Gaorr, or' FRANKFORD, PENNSYLVANIA.

MECHANICAL TIME-FUSE.

Specification of Letters Patent.

Patented Aug. 5, 1919.

Application filed July 6, 1918. Serial N0..243,577.

7&0 all whom it may concern:

Be it known that I, HOWARD M. GROFF, a citizen of the United lStates, residing at Frankford, Pennsylvania., have invented certain new and useful Improvements in Me'- chanical Time-Fuses, of which' the follow-` ing is a specification.

My present invention relates to improvements in mechanical time fuses and has among itsl objects toproduce a 'mechanical to fire. after a predetermined interval of time, and will be reliable in its action, and which is also provided with means enablingl it to be exploded by impact.

Other objects will appear frointhe following description.

The invention includes the novel features of construction and arrangement and combination of parts Hereinafter described and.

defined by the appended claims, an embodiment and some modifications of my invention being illustrated in the accompanying drawings, in which, i

Figure 1 is a transverse vertical section through a mechanical fuse according to one lform of my invention.

Fig. 1a is a detail view of a modification. Fig. l"l is a detail of lmechanical setter.

Fig. 2 is a section on line Q2 of Fig. 1.v

Fig. 3 is a plan view of thetime ring (the cap being removed) and with the main portion of body contained therein shown in section onthe line of the locking pin 21.

Fig. 4 is a partial 4-4 of Fig. 3.

vertical section on line Fig. 5 is a sectional detailview illustrating. a modification. -v

Fig. 6 is a similar view of a further modlfication, and Fig. 6n a detail view.

Fig. 7 is a similar view of a still further modification, and Figs. 7a and 7 b detail views.

Referring by reference characters to these drawings, in which the like characters designate the same parts throughout the several views and referring first to the form shown on Figs. 1 to 4, inclusive, the numeral 1 designates the body or carrier for the various partsand which body is intended to be applied to or inserted'in the projectile in the usual or any approved manner.

This body hasa plurality of'successively reduced cylindrical portions 1a and l? and tatable time 'ring-2 which has an inner annular wall 2a litt-ing the wall l of the body and guided thereby. Said annular wall is extended upward above the annular wall 1 to provlde an annular chamber for the main .spring barrel and main spring hereinafter.

described. The body 1 has a central cham'- 'ber to carry the fuse parts, also hereinafter described, and closure thereof isefected by time control mechanism has lower and upper annular. walls 15a and 15b connected by a horizontal wall 15c beneath which is located the main spring 16, one end'ofwhich is secured to the wall 15a by suitable means such asrivet 20 and the other end to the body or casing by pin 20. v

The main spring thus tends constantly to rotate the main spring barrel which, when rotated, releases the firing mechanism in the manner hereinafter described.

rfhe main spring barrel is, however, norf mally lockedagainst movement by the barrel locking pins 19, preferably two in numencircling these reduced portions is `a ro- .spring barrel 15 constituting a part of the y 'ber and diametrically opposed. These are slidablyrmounted in openings in the wall of the time ring and are pressed in by springs 18 within the cap screws 17 which 'are tapped into the enlarged outer'parts ofthe locking pin openings.- By means of these springs the pressureor tension on the pins may be adjusted or varied at will. The pins engage'eorresponding' openings .in Athe wall 15b of the main spring barrel and thus lock it against movement, but, the compression of the springs being properly-adjusted, the rotaryrmovement given the projectile by the rifling of the gun will cause the pins to fly outward under the centrifugal action, releasing the main spring barrel so that it will be free to be rotated by the spring.

. The time controlled firing means comprises a cylindrical plunger 26 guided in the axial cylindrical opening or passage in the body and having inits hollow center the booster charge which is fired by the time Y by a plunger release pin 21 which has a wedge shaped or beveled nose engaging a correspondingly shaped recess in the wall of the plunger. Normally the pin 21- is held in locking position by itsouter end bearing against the inner face of the flange 15b of the spring barrel. Said flange, however, is provided with an opening 15X, which,

.l as the barrel is rotated by the, spring7 comes into aliivement wit-li the pin, permitting the lthe ring pin 23.

in Fig. 1, is screwed into a threaded open-- latter to be forced back by theaction of the plunger spring and the beveled end of the pin and wall of .the recess engaged thereby,

the plunger being forced outward by its spring to cause' the rimer 25 to contact with lll-he firing pin, as shown,

ing in the outer end of the cap from the outside, but if desired it may be screwed in from the inside as illustrated in Fig. .1*

j at 23a.

From the foregoing it will be evident that the interval of time which elapses between the firing of the projectile and the release of the plunger is determined by the amount of movement of the spring barrel or in other .words the distance t-he latter has to travel to bring the openingv 15X into line with the plunger release pin. This-is determinedby the position or adjustment of the timing ringv which is rotated, together with the spring `barrel connectedthereto by the locking pins, to bring the opening 15X nearer to or farther from the release pin 21. It will lbe understood that the main spring is wound up at the time the parts are assembled.

Suitable graduating marks are provided onv the time ring indicating seconds and suitable fractions thereof, fifths for example, c0- operating with a setting mark.

Too free rotation of the time ring may be prevented by any suitable means, as for example a washer of suitable friction material operating in conjunction with the pressure exerted by the closing cap and interposed between the time ring and body as indicated at 4. v

To prevent the timing ring being turned by hand sufficiently to bring the opening 15X inlto line with the release pin 21 and thus firing the charge I provide a safety pin 33 interposed between the time ring and tain amount of friction tending to retard the rotation of said barrel but this friction may vary due to inequalities in the'spring 27, t. and this is compensated for and supplemented by a plunger (or plungers) 36 sliding in la suitable vertical opening in the vtiming ring, as shown in' detail in Fig. 4,

the pressure of which may be determined by pressure spring 35 and screw cap 34.

It is desirable that means be provided for mechanically setting the fuses to secure rapid duplication of the same setting.

To this end I provide the time ring with a projection or contact member 30 which may be conveniently lield in a recess in the ring lby a locking pin 29, and the body l, While another rejection or contact member 32 is similarly held bypin 31. These projections are designed to cooperate with a mechanical fuse setting device of standard construction on the gun carriage which, as it forms per se no part of the present invention, is not shown herein.

engaging a fxedpart ofthe setter and projection 30 engaging a rotatable ring in the fuse setter. v

It rsuffices to say that the time fuse would be inserted in the mechanical setter with projection 32H00 The movement of rotating ring and pro? i jection' 30 would be controlled by an adjustable stop. A"

To insure the firing of the shell in the event that the time element fails to act I provide percussive means for ring the shell upon striking any object, one form of which means is shown in Fig. -1.

This comprises a percussion plunger 7 which has a head portion guided in the cylindrical chamber formed by the annular flange of the bottom closing screw cap or member 5. The plunger 7 has a reduced portion with a central.; cylindrical passage and an inwardly extending or overhanging lip 7a at its upper end against which the percussive primer 12 is held by the tubular screw member 11. The impact of the shell causes the percussive plunger 7 to be driven forward by its inertia, which results in the primer'being fired by the percussive firing pin 28 screwed into a threaded opening in the body. l

To prevent the percussive plunger 7 from accidentally moving forward I insert in the cylindrical opening in the bod)7 above the base of the percussive plunger a sleeve 6 against the head or flange of the percussive plunger, thus locking it against forward movement. A plunger release ring 9 is provided which is slidably fitted within the sleeve 6 and is normally pressed away from the plunger 7 by an interposed helical spring 8 which also serves as additional means for holding the plunger in its rearward position.

Vllhen the shell is fired from the gun the inertia of the ring 9, which is made of suitable weight for this purpose, forces it back against the tension of spring 8 which results in the spring tongues 6 being forcedl outwardly into alinement with slots or recesses 6x in the sleeve 6.

The ring 9 has aixed to its inner wall a sleeve 14 provided with inwardly defiected spring tongues 14a which, as the ring moves rearwardly, engage beneath the. 'annularthe cylindrical extension of shoulder 7* of the plunger "and lock the ring in its rearward position. i

During the flight of the projectile the coupled elements are prevented from creeping forward under the gradual retardation of the speed of flight by the spring 13. interposed between the front end of the plunger and the' wall of the body around the firing pin.

In Fig. 5 I `have shown a modification of the percussion element arranged to provide an additional powder charge yto insure the firing of the shell. ln this the body is cored out to a larger diameter and a sleeve 50 encircles and acts as a gui e for the percussive plunger, the annular space 41 being filled with powder. '40

In this form the closingy cap to provide further powder powder is heldin place by muslin disk 1()8L and screw washer 10", which are secured in place by spinning over the flange 5X of closing screw.-

In Fig. 6 I have illustrated an arrange ment whereby the'firing of the shell by the time plunger is made independent of the lpermissive element.

lA. passage 42 is bored through the body to the space occupied by the booster charge is milled out space, and the (not shown in this figure) and this spacey may be filled with gun cotton,- the outer end of the passage being closed by-a plug 52. Said space communicates withthe powder spacel 41 by a powder filled branch passage 423.

Another passage 43 bored into the body from the opposite side and communicating with the space above the percussive primer is filled with gun cotton which, when fired.I ignites the powder charge by the powder in branch passage 43a.

In this form have showna modification of the percussive plunger.

In this form the percussive plunger 7h is '41.by the firing plunger and the percussion vfiring pin independently takes place. The

made tapered, and the release ring 9h is provided witha correspondingly tapered portion, slotted vertically to provide spring tongues 1h'. These expand or spread outwardly as the ring is driven down and by theiifrictional engagement hold the release ring in such depressed or rearward position.

`Fig. 7 illustrates another arrangement whereby the ignition of the powder charge ring plun er is recessed-to provide for retention of t e stab primer 53 and the firing plunger spring 54. A booster Charge 55 can be lntroduced to insure the ignition of the gun cotton charge 42.

ln this form the arrangement of the per- '.cussion element is reversed, the firing pin being incorporated in the moving element and the percussion primer mounted directly in the body.

The percussion firing pin 56 is retained in the percussion firing pin housing 57 by the safety pins 58 held in position by the safety pin springs 59. The percussion firing pin is thus he d below the upper surface of the percussion firing pin housing so that accidental discharge of the percussion primer cannot occur until the percussion firing pinis armed. The acceleration of the pro- `]ectile at the moment of discharge causes the percussion firing pin 56 to seat itself on vthe .shoulder of the percussion firing pin housing 57, releasing the pressure of the percussion firing pin arming springs 61 from 100 the safety pins 59. The centrifugal force developed by -the rotation of shell caused the rifiing of the gun releases th safety pins 59 and allows the percussion firing pin larming springs 61 to project the percussion 105 firing pin forward until the locking pin spring 62 forces the locking pinsy 63 into the `annular groove in' the percussion firing pin vhousing locking the percussion firing pin in Ian armed position. klo The percussion plunger sleeve provides a housing for the various parts and retains the safety pin springs in position.

Having thus described my invention what l claim is: y 1. A mechanical time fuse comprising a vsuitable body, a spring pressed time firing plunger therein, a plunger release pin carried by the body having a beveled end engagmg a corresponding recess in the plunger, a spring barrel having an annular fiange normally holding said release pin iii locking position and having an opening adapted to register with lsaid pin, a spring tending to rotate said barrel, an adjustable time ring encircling said barrel, radially movable pins normally connecting said spring barrel and time rin springs bearing on said pins, and means or varying the tension on said springs.

2. A mechanical time fuse comprising a suitable body, a spring pressed time firing plunger therein, a plunger release pin carried by the body having a beveled end engaging a corresponding recess in the plunger, a spring barrel having an annular iiange normally holding said release pin in locking position and having an opening adapted to register with said pin, a spring tending to rotate said barrel, an adjustable time ring encircling said barrel, radially movable pins normally l connecting said spring barrel and time ring, springs bearing on said pins, 'means for varying the tension on said springs, and means for limiting the extent of adjustment of said time ring.

3. 'A mechanical time fuse comprising a suitable body, a spring pressed time firing plunger therein, a plunger release pin carried by the body having a beveled end engaging a corresponding recess in the plunger, a spring barrel having an annular flange normally holding said release pin in locking position and having an opening adapted to register with said pin, a spring tending toA rotate said barrel, an adjustable time ring encircling said barrel, said time ring and said body having means for limiting their relative adjustment comprising a fixed pin' in one of said parts engaging an arc shaped groove in the other part.-

4. A mechanical time fuse comprising a suitable body, a spring pressed time firing plunger therein, a plunger release pin carried by the body having a beveled end engaging a corresponding recess in the plunger, a spring barrel having an annular flange normally holding said release pin in locking position and having an opening adapted to register With said pin, a spring tending to rotate said barrel, an adjustable time ring encircling said barrel, and adjustable fric,- tion means for retarding the rotation of the spring barrel.

5. A mechanical time fuse comprising a suitable body, a spring pressed time firing plunger therein, a plunger release pin carried by the body having a beveled end engaging a corresponding recess in the plunger, a spring barrel having an annular Harige normally holding said release pin in locking position and having an opening adapted to register with said pin, a. spring tending to rotate said barrel, an adjustable time ring encircling said barrel, and adjustable frict-ion means for retarding the movement of the spring barrel comprising a spring pressed pin' bearing on said barrel and means for varying the pressure of said pin.

6. A mechanical time fuse comprising a body having a tubular bore, a spring pressed plunger therein, a booster charge and primer carried thereby, a plunger release pin carried by the body and normally engaging said plunger, a spring barrel having a ring ated means normally locking said barrel to said time ring, and a cap secured to said body and holding said barrel and time ring in position, and a liring pin carried by said cap.

body having a tubular bore, a spring pressed g plunger therein, a boosterv charge and primer 3 carried thereby, a plunger release pin car' riedk by the body and normally engaging said plunger, a spring barrel having a ring or flange normally holding said release pin against movement and having a recess to aline with said pin, an adjustable time ring encircling said barrel, and friction means interposed between said time ring and body.

8. A mechanical time fuse comprlsmg a suitable body, a time firing plunger slidably mounted therein, a release pin carried by said body and normally engaging said plunger, a rotatable ring overlying the end of 90 the release pinto hold it in engaging position, said ring having an opening to aline with said release pin when theA ring is moved to a determined position, means for rotating said ring, and centrifugally operated locking means normally holding said ring against rotation, -Said body and .said ring having peripheral recesses, time settin projections seated in said recesses, an locking s aid projections in said recesses.

l." A mechanical time fuse comprising afsuitable body, a time firing plunger slidably mountedtherein, a release pin carried by said body and normally engaging said plunger, a rotatable ring overlying the end of the release pin to hold it inengaging position, sa-id ring having an opening to aline. With said release pin when the ring is moved' to a determined position, means for rotating ing means normally holding said ring against rotation, and percussive firing means also carried by said body. ,l

i 10. In combination, a suitable or casing having a Stationary ring pin, a percussive plunger slidably mounted in the casing, carrying a primer to coact with said pin, spring locking tongues normally engaging said plunger, a slidable ring movable by its inertia to disengage said tongues from the plunger, a spring interposed between said ring and plunger tending normally to separate them, and means for locking the ring lin its tongue holding position.

11. In combination, a suitable body or casinghaving a fixed firing pin, and a central chamber, a percussion plunger having a main portion slidably fitting in .said chamber, and having a reduced `portion carrying a primer to coperate .with said pin, a sta- 7. A mechanical time fuse comprising agm pinsh tionary sleeve fitted in said chamber having spring tongues normally engaging theplunger, an inertia rlng interposed betweensaid sleeve and the reduced portion of the plunp movable to disengage the tongues said reduced portion of and said ger' and from the plunger, the plunger having a shoulder,

'spring pressed time inertia ring a tongue or pawl to engage said shoulder when the inertia ring is moved.

13. In combination, a body or casing having a cylindrical opening or chamber at eachv end with an intervening ported Well, a plunger carried in the forward chamber carrylng .i primer and I booster charge, mechanica ime controlled means for releasing said plunger, a cap closing said chamber and holding said time controlled means in position, ger in the rear chamber carrying a primer, a firing pin carried by said ported Wall to coact with said` last named primer, inertia released means for .holding said plunger against movement, and a ported cap closing the rear chamberl and confining said pereussive plunger and means in position.

In testimony whereof, I aliiX my signature.

. HOWARIJM. GROFF.

a percussive plun- 

